Triple adjustment shankless tool bit and holder therefor



Dec.' 20, 1938." E. RANEY.

TRIPLE ADJUSTMENT ,SHANKLESS TOOL BIT ND HOLDER THE REF-0R Filed oct.2'?, 193e ATTORNEY Patented Dec. 20, 1938 UNITED STATES TRIPLEADJUSTDIENT SHANKLESS TOOL BIT AND HOLDER THEREFOR Ernest Reaney,Bridgeport, Conn., assigner to The 0. K. Tool Company, Inc., New York,N. Y., a corporation of New Yorkk Application October 27, 1936, SerialNo. 107,862

1 Claim.

This invention relates to insertable bit metal cutting tools of thelathe type and is concerned more particularly with an improved methodand means of resetting the tool bit in the holder to 5 obtain anadjustment of the bit in three directions simultaneously.

In its more specific aspects the invention is best adapted to shanklessbits and holders such as disclosed in my copending application SerialNo. 24,023, led May 29, 1935, with respect to which this invention is animprovement.

In my aforesaid copending application there is disclosed a tool holderadapted to hold one of a plurality of different styles of L-shapedcutting bits. The contour of the bit receiving aperture and thecomplemental portion of the bit are so constituted, however, that thecutting edge of the bit may be adjusted laterally only to. adapt thetool to either a right hand or a left hand cutter. Such a constructiondoes not admit compensation being made for reduction in height or lengthof the bit, due to the grinding off of layers in resharpening.

In the machining of certain pieces, such as cylindrical work, hard spotsare occasionally encountered by the cutting point of the tool andfrequently the extreme forward end of the tool bit receives a fractureor becomes badly chipped. Heretofore, it has been necessary not only toremove the bit from the holder for regrinding but also to unclamp andreset the holder in the tool post of the machine in its proper advancedand elevated position to allow for the foreshortening of the bitoccasioned by grinding va new contour on the end thereof.

This mode of operation was troublesome and difficult to make and couldbe practiced only once or possibly twice because each time the end ofthe bit was ground anew, it materially shortcned the bit, therebyreduced its overhang, and it was not long before it became unt for use.

The present invention aims to overcome dis-l advantages of this natureand to render available a construction in which the cutting point of thebit may be repeatedly advanced relative to the holder to compensate forthe foreshortening of the bit resulting from the grinding out offractures occurring at the forward end.

A further object of the invention is to render available an insertablebit tool in which the original or normal overhang of the bit from theholder, and its position vertically therein, essential `and necessary intools of this character, may 55 be preserved and retainedr afterrepeated resharpening operations have been performed upon the cuttingedges of the tool bit.

Another objective of the invention is to accomplish the tripleVadjustments labove mentioned without the use of auxiliary lockingdevices, 5 shirns, etc., and to provide an insertable bit tool in whichthe reactionary tooling forces are utilized in assisting the` manuallyoperable clamp in holding the bit firmly in its adjusted or resetposition in its seat in the holder. 10

A preferred manner of carrying out these objectives is to form an opensided bit receiving recess in one end of a tool holder, dened by atleast two planes compoundly inclined relative to each other. vides thelower seating surface for the tool bit and terminates in a rear abutmentwall that slopes laterally upwardly and forward relative to thecompoundly sloped bottom wall, the marginal edges of the two surfacesconverging in the 20 general direction in which the triple adjustmentforward, upward and laterally, is desired. With a right hand holder theconvergence is toward the right and with a left hand holder theconvergence is toward the left. 25

The base portion of the L-shaped tool bit is provided with similarlyinclined and sloped bottom and rear surfaces, and when the bit is movedlaterallyin the recess it is caused to advance simultaneously in aforward direction, in an up- 30 ward direction and in a lateraldirection. After the bit has been properly positioned it is then clampedpositively in place in the holder. Interlocking means preferably in theform of serrations are provided between one of the pairs of 35 seatingsurfaces for locking the bit against twisting and lateral shift in theholder under the impacts of the tooling operation. By extending theserrations in a longitudinal direction and transverse to the generalslope of the compoundly in- 40 clined seatingsurface a positive means isprovided for locking the bit to its seat. By correlating the angles ofthe planes of the bit seating surfaces with the spacing of theserrations, the vertical and forward shift of the bit relative to theholder, when the bit is indexed one or more serrations, may be set toyield an advance commensurate with the amount removed during a vnormalresharpening operation. When the bit is reinserted in its socket, thecutting edge thereof will. be caused to assume its original position.

Other objects and advantages will be in part i dicated in the followingdescription and in part rendered apparent therefrom in connection withthe'annexed drawing. 55

The lower wall of the aperture pro- 15` To enable others skilled in theart so fully to apprehend the underlying features hereof that they mayembody the same in the various ways contemplated by this invention, adrawing depicting a preferred typical construction has been annexed as apart of this disclosure and, in such drawing, like characters ofreference denote corresponding parts throughout all the views, of which:

Figure 1 of the drawing is a side elevation of a lathe tool embodyingthe principles of this invention.

Figs. 2 and 3 are plan and end views respectively thereof illustratingin dotted lines progressive forward, vertical and laterally adjustedpositions of the tool bit.

Figs. 4 and 5 are side and end views respectively of a holderincorporatingthe principles of this invention equipped with analternative form of bit clamp.

Fig. 6 is a geometric diagram more clearly illustrating the originationand relation between the compoundly inclined seating surfaces and thetool axis for effecting triple adjustments ofthe bit.

Fig. 1 of the drawing discloses the invention embodied in a heavy dutylathe tool consisting of three main elements, a holder member I0, a bitmember II and a clamp device I2. The holder I is preferably made ofchrome nickel steel, for strength, and is provided with an open sidedbit receiving recess I3 at the forward and depending end I*l thereof.The lower wall I4- of the recess forms the main seating surface for thetool bit and is inclined rearwardly and sloped laterally, at anglesapproximately and 10 degrees respectively, thereby forming a compoundlyinclined flat seating surface of ample propor-v tions for the bit II.The bottom wall I4 terminates in a relatively inclined rear Wall I5,which wall is also inclined from a plane perpendicular to thelongitudinal axis of the holder, i. e., the wall I5 is inclined withrespect to the bottom wall I4 and slopes diagonally across the holder atthe base or rear of the bit recess.

Fig. 6 of the drawing illustrates more clearly the origination andrelation of one seating surface to the other and to the axis of theholder whereby a tool bit complementally formed may be repositionedlaterally therein and advanced simultaneously in three directions. Inthis figure, the vertical plane a, b, c, d, is indicated as beingperpendicular to the longitudinal axis of the holder III. The horizontalplane b, c, f and e is perpendicular to the said vertical plane andextends longitudinally of the holder.' Starting at the point h, thelower surface I4 extends forwardly and upwardly making an angle ofapproximately 5 with the horizontal plane b, c, f and e. From point b,the lower surface also extends upwardly in a lateral direction at anangle of approximately with respect to the said horizontal plane, thusproviding a flat compoundly inclined seating surface, the highest pointof which is diagonally opposite the lowest point b,

'Ihe rear abutment surface I5 is preferably inclined relative to thesurface I4 soas to form a V-shaped recess, and to obtain the tripleadjustment feature, the line of intersection b, z' of the surfaces I4and I5 is made to occur in the transverse plane a, b, g, h which asillustrated in Fig. 6, extends transversely of the holder at an angle ofapproximately 10 from the perpendicular plane a, b, c, d. The line ofintersection of the surfaces I4 and I5, accordingly, is caused to extendforwardly and upwardly from the point h and indicates the line ordirection of shift of any given point on the tool bit. By appropriatelyvarying one or more of the angles of incline, the direction of line bi,i may be altered to vary the ratios of movement between the forward,lateral or vertical movements of the tool bit.

The forward incline of the surface I5 away from the transverse plane a,b, g, h, cooperates with the downward and rearward incline of thesurface I4 in locking the bit on its seat. The included angle thesurface I 4 makes with the surface I5 may be increased to substantially90 before the benefit of the overhang for that purpose is lost.

, Referring more particularly to Figs. 1-3 of the drawing, the lowerseating surfaces of the bit and holder are illustrated provided withcomplementally formed intertting serrations I5 extending longitudinallyof the holder I Il, which also is in a direction transverse to bothangles ofincline of the lower seating surface I4. A multiplicity ofabutments extending transversely to the general diagonal slope of thesurface I 4 are thereby provided and serve positively to lock the bitagainst twisting on its seat or against lateral shift in the generaldirection of the line b, i.

By correlating the spacing of the serrations with the angles of slope ofthe walls I4 and I5, the serrations perform the further function ofdefinitely indicating the increment of forward, vertical, and lateralshift of the bit relative to the holder for each serration of lateralmovement. In the example illustrated, where the angles of slopeindicated are 5 in a vertical longitudinal plane, 10 in the verticalperpendicular plane, and 10 in the transverse plane, and with serrationsspaced to the inch, the lateral stepping of the bit one serrationeffects an adjustment forwardly of approximately .01 and verticallyapproximately .01" which is the amount that would be ground away duringa normal resharpening operation. Compensation for more severe grindingoperations may be effected by laterally stepping the tool bit two ormore serrations. Figs. 2 and 3 of the drawing illustrate in full anddotted lines positions az, y and e the progressive movement of the bitin the three directions simultaneously.

To clamp the tool bit in adjusted position, a screw operated clampoperable from the top or from the underside of the holder may beprovided. In Figs. 1-3, the top clamp is illustrated Ywhich Vcomprises adownwardly and rearwardly acting clamp member il that extends forward inoverlying relation with the tail portion I8 of the tool bit. The memberI l is formed with a sleeve portion I9 that slidingly fits in a recess20 in the holder Ill. A clamp screw 2l loosely fits Ythe sleeve I9 andhas a threaded connection with the body of the holder. Preferably theaxis of .the .screw 2l and sleeve I9 is inclined forward relative to theseating surface I4 so that the clamp exerts a rearwardly acting force onthe bit as well as a vertical force. By actuating the clamp screw 2I ina clamping direction the bit is firmly clamped between the surface I4and overlying portion Il and against the rear abutment wall I5,

In the construction depicted by Figs. 4 and 5 the same sturdy clampingaction results. In this type of clamp, the overlying portion 23 of theholder is integral therewith and a Vertical and rearwardly acting clampelement 24, underlying the bit, effects the clamping action. The clampelement 24 slides on the horizontal surface 25 of the holder and isguided by the key 26 and draw bolt 2l. The upper surface Illa of themember 24 and rear wall l5al are relatively compoundly inclined, asabove explained in connection with Fig. 6, and when the member 24 isurged rearwardly by the clamp nut 28, a clamping of the bit betweentheoverlying portion 23 and seating surface Elia, and simultaneouslyagainst the rear abutment wall i5a occurs. -In this form of clamp, theundersurface 29 of the overlying shelf 23 slopes laterally coincidentlywith the lateral slope of the seating surface ille, whereas, in theconstruction represented in Fig. l the vertical movement of the topclamp takes care of any variation in cross-sectional thickness of thebit as the latter is moved laterally and the undersurface of theoverlying portion il may therefore be straight. With either form ofclamp, however, triple adjustments of the bit may be simultaneouslyobtained.

By the aid of this invention it will be seen that an operator may clampthe tool holder in the tool post of the machine in the approximateposition, and then adjust the position of the bit at the forward end toplace the cutting edge thereof in the precise position vertically,laterally or forwardly as the nature of the machining operation demands.Af ter the cutting edge of the bit has become dulled it is removed fromthe holder and resharpened by grinding off a layer from the top surface.In the event of a bad fracture occurring at the forward end of the bit,it may be removed by grinding on the front end instead of all from thetop.

End grinding of the bit materially conserves its height and inasmuch asthe foreshortening of the bit is compensated for by this invention,objectionable loss in bit overhang is not occasioned. As the bit isreduced in height, due to regrinding from the top, its originalelevation may be restored by progressively stepping the bit laterallyandreclamping it in the desired .elevated position.

The life of any given tool bit may, by this invention be materiallylengthened, and relatively expensive bit stock may be reground at itsend and top surfaces repeatedly and compensation quickly and easily madefor the amount ground away.

While the invention has been disclosed herein, in connection with alathe tool, it will be understood that it is equally applicable to othertools of `that general type, such as used on planers, boring machines,shapers and analogous machine tools. Without further analysis, theforegoing will so fully reveal the gist of this invention that otherscan, by applying current knowledge, readily adapt it for variousutilizations by retaining one or more of the features that, from thestandpoint of the prior art, fairly constitute essential characteristicsof either the generic or specic aspects of this invention and,therefore, such adaptations should be, and are intended to be,comprehended within the meaning and range of equivalency of thefollowing claim.

Having thus revealed this invention, I claim as new and desire to securethe following cornbinations and elements, or equivalents thereof, byLetters Patent of the United States:

A lathe tool combining an elongated holder memberhaving a recess at oneendthereof adapted to receive an upstanding tool bit, said recess beingdened by a lower rearwardly inclined bottom seating surface and a rearabutment wall that extends crosswise the holder at an angle to a planeperpendicular to the longitudinal axis thereof, said bottom seatingsurface being also sloped laterally relative to a plane perpendicular tothe vertical axis of the holder and in a direction transverse to saidfirst mentioned incline, with the line of intersection of said laterallyinclined surface and said rear wall lying in a plane disposed at anangle to an imaginary plane perpendicular to the longitudinal axis ofthe holder; a shankless L-shaped tool bit fitted to said recess andadapted to abut against said rear abutment wall of the recess in allpositions of adjustment, said bit having an upper clamping surfaceextending in a plane substantially perpendicular to the vertical axis ofthe bit and an upstanding portion affording an upper front cutting edgeand material for resharpening by successively removing layers from thetop or end surface thereof whereby said upstanding portion issuccessively reduced in height and length, said bit also having itsbottom surface inclined relative to its said clamping surface in twodirections complemental to the incline and slope of the bottom seatingsurface of said recess and its rear surface transversely inclinedcomplementally to the incline of said rear wall of the recess; a seriesof interfltting serrations between said bottom surface of said bit andrecess extending in the direction of said irst mentioned incline andtransversely to said line of intersection, said serrations incooperation with said lateral slope of said bottom wall and thetransverse slope of said rear wall serving as positive means forindexing said bit forwardly and simultaneously vertically inpredetermined increments to compensate for loss in length and heightresulting from the resharpening operation; and inanualy operable screwclamp means coacting with said holder for urging said bit rearwardly inclamped position in said recess.

ERNEST REANEY.

adapted to stand on said seating surface

